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never heard that sentence before. it's may be a typo or a slang in small groups
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LiuYan 刘研Dec 20 '13 at 9:56

I am certainly sure that your friend make the mistake! Your friend may ask for your plan. To translate a wrong sentence is not the right way. So for your first question , I guess they are asking 今晚怎么样(How about tonight？). For question two: I may translate to 今晚几点开始？ or 今晚几点见面？
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einverneDec 23 '13 at 4:50

@LiuYan刘研: English tip for you if you're interested: We never say "a slang", just "slang". Kind of like "information". (-:
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hippietrailFeb 14 '14 at 9:02

Putting the phrase on Google gets just 9 hits, 4 of which come from your question. It is safe to agree with the people below who say this is not something many Chinese people would say.
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Colin McLartyDec 5 '14 at 5:49

Your friend's expression is similar which is highly irregular and non-standard. Coincidentally, my friend and I also use "怎么个意思" in asking for advice and comments on recreational plans, attitudes and even just for greeting.

Usually the meaning of this kind of expression is gradually formed during daily usage among a small group of close friends and it might be difficult for outsiders to get to know the meaning at first glance.